Electrowetting is an emerging technology for a variety of display applications, such as reflective displays, transmission displays and light shutters.
The general principle of electrowetting technology is shown in FIGS. 1A and 1B. Referring to FIG. 1A, when no electric filed is applied, a colored non-polar liquid 105 may naturally spread over an underlying layer 106. An electrowetting display unit 100 may show the color of the non-polar liquid 105 to a viewer, thereby limiting the ability of light to pass through the electrowetting display unit 100 as indicated by the filled in arrows of FIG. 1A. On the other hand, when an electric filed is applied as illustrated in FIG. 1B, due to the electrowetting effect, a conductive liquid 104 will approach the underlying layer 106 which causes a change in the shape of the colored non-polar liquid 105 or pushes aside the non-polar liquid 105, resulting in transmission of incidence light through the underlying layer 106 as indicated by the empty arrows in FIG. 1B replacing the formerly filled in arrows shown in FIG. 1A. Because the display brightness depends on the contraction of the colored non-polar liquid 105, it may be desirable to improve the display contrast by controlling the light transmission through the electrowetting display unit 100.